Propelling pencil



Aug. 13, 1940. H. M, FARRINGTON PROPELLING PENCIL Filed Nov. 9, 1937 Patented Aug. 13, 1940 UNlTED STATES PATENT orties PROPELLING PENCIL Application November 9, 1937, Serial No. 173,611 In Great Britain November 9, 1936 3 Claims.

This invention relates to mechanical lead penoils or pencil actions of the type in which an internal lead-carrying member is pressed forward by hand and returned under spring influence,

wedging or clamping means being provided for gripping the lead preparatory to writing.

A mechanical pencil or pencil action, according to my invention, is characterised in that a guide tube or lead carrier slidably disposed within an outer body or casing has a forward part or a portion intermediate its ends formed with one or more longitudinal slits or slots so as to provide non-slotted portions above and below the slotted portion, and a part of such slotted portion is or are provided with tapered or like projection or projections or enlargements with which conact a collar, sleeve, or abutment member disposed within the pencil body or casing; the arrangement being such that when said sleeve, or the like, 20 engages with said projection or projections of the slotted portion of the guide tube or lead carrier, said slotted portion is caused to yield and grip or clamp the lead for a substantial part of its length in order to afford adequate holding of the lead without likelihood of its being broken.

The principal object of the present invention is to present an improvement in mechanical lead pencils of the aforesaid type.

A further object of the present invention is to present a mechanical lead pencil which is economical to produce and yet which is simple to operate.

Another object of the present invention is to present a mechanical lead pencil of the aforesaid 35 type wherein the lead` or aligned pieces of lead are ensured of a continuous and even passageway therefor, which prevents breakage or clogging of the lead in passing therethrough.

Other objects of the invention will be obvious 40 from the following detailed description in which reference is made to the accompanying sheet of drawings illustrating the invention.

In said drawing:

Fig. l is a longitudinal section of a mechanical pencil constructed in accordance with. my invention and showing the saine in normal. condition for writing, the lead being gripped by its guide tube or carrier.

50 Fig. 2 is a perspective View of the lead-gripping part of the guide tube.

Fig. 3 is an enlarged longitudinal section of the forward portion or point section end of the pencil in normal writing position as in Fig. 1.

55 Fig. 4 is asectional elevation similar to Fig. 3,

(Cl. 1Z0-m47) but showing the guide tube with lead projected asin a feeding stroke.

Referring now to the pencil illustrated in Figs. l. .to 4, inclusive, there is secured at al to an outer casing a a tapered member or point section 5 b, however, casing a and point section b may be in one piece, and within and extending substantially throughout the length of said casing a there is slidably disposed a guide tube or lead 4 carrier c having its forward end projecting into 10 a central passage b1 of point section b. Said guide tube c has a forward part or portionintermediate its ends provided with one or more longitudinal slits or slots as at c1 so as to form nonslotted parts above and below the slotted portion. In the example illustrated, guide tube c is provided with two diametrically opposed slots cl and on a midway or substantially midway part of such slotted portion of the guide tube there are formed tapered projections or integral enlarge ments c2 which are disposed within a collar or sleeve member d, d1, d2 situated within the casing a and slidable on guide tube c. Said sleeve,

'which provides a tapered passage d1 and an annular larger recess d2, is confined but movable ben tween an annular indentation a2 of casing a and the adjacent inner end of point section b so that, when its tapered passage `d1 engages with said tapered projections c2 of guide tube c, the longitudinally slotted portion c1 of the latter is '30 caused to yield inwardly or contract against its inherent resilience and grip or clamp the lead c in said guide tube c; thus the lead is gripped for a substantial part of its length without danger of breakage as sometimes occurs in pencils of V this type wherein a clamp device having openended jaws acting on a small part of the lead has a tendency to cut or break the latter, but when the projections c2 of lead-tube c are in alignment or register with the annular recess d2 40 of sleeve d, d1, d2 the binding elfect of the tube on the lead ceases.

The end of said guide tube c remote from point section b is fitted with a removable cap or knob piece f which may carry an eraser piece, not shown.

A coiled spring y is positioned within the central passage bi1 of the rpoint section and has its ends respectively in abutment with the forward end of guide tube c and a shoulder or ledge b2 50 formed at the top of a reduced passage b3 of the point section so that guide tube c is normally maintained in its uppermost position, and at the same time the lead is gripped due to the tube projections c2 being held in operative con- 55 tact with the tapering passage d1 of sleeve d, d1, d2 and the stopping engagement of the top of said sleeve with the annular indentation a2 of casing a.. A washer h provided in casing a assists in the guidance of tube c and also provides a supporting floor for the rells.

The operation of the pencil is as follows:

Upon guide tube c being pushed by hand inward relative to casing a, as in Fig. 4, by its knob piece f, the guide tube moves forward against the resistance of spring g with lead e and with sleeve d, d1, d2 still squeezing tube c until the front edge of the sleeve moves into Contact with the rear end of the point section b, the extent of its stroke or travel being governed by the distance :r which thus controls the length of lead e projected at each pressing action. On the continued pressing of cap f by the user, the projections c2 of guide tube c move into register with the annular recess d2 of sleeve d, d1, d2 thus permitting this part of the tube to spring open and release the lead e in its newly projected position. Said lead, however, due to its slight frictional contact in the passage b3 of point section b, does not move further outwardly.

On the user releasing pressure on cap f, guide tube c returns to its normal position under pressure of spring y, in which movement the tube projections o2 return sleeve d, d1, d2 until the back of the latter engages against stop a2 of casing a. In this movement the lead is not gripped, being left in its newly projected position, but when the motion of sleeve d, d1, d2 is arrested, the spring pressure completes its backward stroke by forcing the projections c2 of tube c into the tapering passage d1 of the sleeve, and lead e is regripped ready for writing and also ready for a further projectory stroke as and when required.

Other stops or abutments may be provided at the forward or rear end of the pencil to regulate or control the projection or outward travel of` the lead on each ejectory stroke of the pencil. Further. a rotary or lever device may be fitted to the pencil in lieu of said cap or knob y for the purpose of imparting the requisite longitudinal movement to the lead carrier c.

What I claim as my invention and desire to secure by Letters Patent is:

l. A mechanical pencil of the character described comprising an outer body having a passage provided therethrough, said passage having a shoulder formed with the wall thereof, a lead guide tube of substantially a constant diameter throughout its length slidably mounted within said body passage, said guide tube having longitudinal slots formed therethrough causing the body portions therebetween to be resilient, a collar slidably mounted within a limited portion of said body passage, projections each having their outer edge inclined relative to the longitudinal axis of and carried by said tube, said collar having a bore in slidable engagement with and tapered similar to said projections and a coil spring having one end bearing against the lower end of said tube and the opposite end thereof bearing against said shoulder in such a manner that when the lead extending from said tube passes through said spring it is guided thereby to the tip of said body passage.

2. A mechanical pencil of the character described comprising a tubular casing, a tapered member having a stepped bore formed therethrough carried by one end of said casing, a lead guide tube of substantially a constant diameter throughout its length slidably mounted within said casing, said guide tube having a portion thereof weakened by longitudinal slots formed therethrough in such a manner as to cause that portion of the tube to be resilient, said resilient portion having projections thereon whose outer edge is inclined relative to the longitudinal axis of said tube, a collar having a bore which tapers similar to said projections slidably mounted within said casing and having said resilient portion with projections slidably mounted Within said tapered bore, said casing having annular indentations therein for limiting the sliding movement of said collar within the casing and a coil spring mounted within said stepped bore with an end thereof bearing against a side of one of the steps and the opposite end bearing against the lower end of said guide tube in such a manner that when the lead extending from within said tube passes through said spring it is guided thereby to said stepped bore.

3. A mechanical pencil of the character described comprising a tubular casing, a tapered member having a stepped bore formed therethrough and an undulation formed upon its periphery, said tapered member having a portion thereof mounted within an end portion of said tubular casing, which casing is crimped about said undulation for retaining the tapered member therein, a disc having an opening formed therethrough positioned within said casing and extending thereacross, a lead guide tube of sub-l stantially a constant diameter throughout its length slidably mounted within said disc opening and spaced from said casing thereby, said guide tube having longitudinal slots formed through l a portion thereof in such a manner as to cause that portion of the tube to be resilient, said resilient portion having projections whose outer edges incline relative to the longitudinal axis of said tube thereon, a collar having a bore which tapers similar to said projections slidably mounted within said casing and having said resilient portion with projections slidably mounted within said tapered bore, said casing having an annular undulation therein for limiting the sliding Y movement of said collar and supporting said disc within the casing and a coil spring mounted within said stepped bore with an end thereof bearing against a side of one of the steps and the opposite end bearing against the lower end of said guide tube in such a manner that when the lead extending from within said tube passes through and is supported by said spring it will be guided thereby to said stepped bore.

HASTINGS MACLEOD FARRINGTON. 

